1. Field of the Invention
This invention relates to computer games systems and it relates particularly to an interfacing device for modifying the manner in which a computer game is played.
2. Description of the Prior Art
A conventional computer games system typically includes a computer containing the main processing unit, a visual display unit (VDU) on which a game is displayed and which may constitute a part of the computer, some form of interactive unit (e.g. a keyboard or joystick) enabling a player or players to react to and influence events during the course of a game, and an external data storage medium (e.g. a game cartridge) that can be plugged into or otherwise connected to the main processing unit and that contains data defining the characteristics (e.g. the rules) or the particular game being played.
In general terms, the main processing unit is programmed to address different storage locations in the external data storage medium, whereby to access the stored data as it is needed.
To that end, the main processing unit generates an address identifying a respective storage location in the storage medium, and this address is routed to the storage medium on an address bus. When the stored data is required, the processing unit sends a request signal to the storage medium, whereupon the data in the addressed storage location is accessed and then routed to the processing unit on a data bus.
The data stored in an external data storage medium determines the characteristics of the game stored therein and typically defines such game parameters as the number of playing units (e.g. cars, planes, etc.), the number of lives ascribed to individual players, the duration of particular events, time limits and speed settings, color and so on.
Generally, computer games require the players to complete various tasks (e.g. to complete a fixed number of laps of a track), and failure to complete a task satisfactorily results in some cases in the elimination of a player from the game. In many games, the players may be ascribed more than one "life," and this can affect the difficulty, or ease, with which the game is played.
With existing systems, the characteristics of a game, and in particular its degree of difficulty, are to a large extent predetermined by the data stored in the external data storage medium. Consequently, existing computer games tend to lose their appeal and present less of a challenge to the player the more times they are played--that is to say the games have limited "playability."